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Author Topic: Would using wave energy reduce coastal soil erosion?  (Read 3465 times)

Offline Airthumbs

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By absorbing some of the energy from a passing wave and converting it to electricity a large area of wave generators might have the positive impact of reducing coastal soil erosion?

One way of controlling coastal soil erosion is the physical manipulation of the waves through redirection of the force but this normally just moves the problem elsewhere, at a local level. I have no idea just how much energy is stored up inside an average ocean wave, or how much of that energy can be converted into electricity.  It may be possible to create a completely calm area using a series of wave generators. 

Could this save the World in Dubai from becoming washed away? Maybe not, they need water flow or the sea around it will become stagnant!    ;D



 

Offline CliffordK

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Would using wave energy reduce coastal soil erosion?
« Reply #1 on: 04/08/2011 04:11:42 »
If you want to counteract the waves, you add a jetty, although your wave machine might also help a bit.  I could imagine creating something like a toilet float connected to a generator...   Which also gives you a good image for the Dubai beach projects!!!!

Anyway, I believe the Dubai "World" already has a Jetty.

http://www.dailymail.co.uk/news/article-1349532/Dubai-islands-falling-sea-Dubai-World-sinks-fund-crisis.html



So many of the Dubai beaches are artificial.  When you read about sand, apparently there are many different types of sand, and not all types of sand are the same.

There is natural Beach Sand, which tends to be reasonably dense, and packs well.
There is Desert Sand, which has something different about it.  Heck, I don't know what the difference is, but it isn't supposed to be as stable.
The, there is Dredged sand. 

Dubai uses a lot of dredged sand to make their artificial beaches. 

The problem is that it isn't the same as beach sand.  It is much more porous, and a lower density.  And, also carries a lot of silt with it.

Dredging and building artificial beaches also changes the entire dynamics of the coastline.

Here is an excellent 3-part article about Florida's beaches "Addicted to Nourishment".
http://www.saltwatercatchbasin.com/Dredging1of3.pdf
http://www.saltwatercatchbasin.com/Dredging2of3.pdf
http://www.saltwatercatchbasin.com/Dredging3of3.pdf

Here is a Q&A on beach nourishment.
http://www.surfermag.com/features/fl_bch-erosion/

Anyway, I'm not surprised that Dubai is having major problems with their artificial beaches.  And, it will likely be a fiasco will endure long after their oil and funding runs out.

There is a group of natural southeast Pacific islands called the Caterat Islands that are sinking...  FAST.
http://en.wikipedia.org/wiki/Carteret_Islands#Flooding
http://en.wikipedia.org/wiki/Sun_Come_Up_(film)

Yet, it is a complicated issue.  The southeast Pacific basin shows higher than average sea level rise. 

http://stevengoddard.wordpress.com/2011/02/18/nasa-sea-level-declining-around-the-us/


This is confounded by ocean currents such as ENSO (El Niņo/La Niņa), but I think it is more than just ocean currents, showing high rates of sea level rise in both El Niņo & La Niņa years.  The region around Indonesia is also very tectonically active, and may be sinking due to earthquakes.

Waves aren't all bad either.  In a stable system, the waves will bring in as much new sand as they remove old sand.  So, getting rid of waves might prevent new sand from being brought in.

Anyway,

If I was going to do beach nourishment for something like Florida, or the Cateret Islands, what I would do is make a deep sea dredge.  Bring the stuff up from far offshore, at least 1 or 2 miles deep.  Go far enough out to sea that one isn't affecting local currents, or local fish estuaries. 

Then put it through a giant centrifuge.  The heavy sands would go to the beaches.  The lighter silt and light sands would then be washed with fresh water from a local river, but cleaned far out in the ocean, then applied as top soil somewhere, including building the internal areas of the island.

As is, with projects like Florida, they aren't cleaning the sand, and everything is done far too close to the beaches.

It would probably cost several times as much to do it the right way rather than what they're doing in Florida, but it would be worth it to not loose islands forever.

Oh..
One other thing.
POPULATION CONTROL.
1,600 people for 1 sq km is way too many people.  No wonder they are addicted to relief supplies as their islands dwindle.
 

Offline Airthumbs

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Would using wave energy reduce coastal soil erosion?
« Reply #2 on: 11/08/2011 01:52:43 »
Thanks for the very interesting information CliffordK.   ;D
 

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Would using wave energy reduce coastal soil erosion?
« Reply #2 on: 11/08/2011 01:52:43 »

 

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